Choke coil



Dec. 30, 1930.

A B. DIBNER CHOKE COIL Filed Sept. 7. 1929 INVENTOR M M w P N w o 4 T Tm RY MB Patented Dec. 30, .1930

PATENT OFFICE! ABRAHAM BERNARD manna, or rnnxsxrnr, new YORK CHOKE COILApplication filed September This invention relates to improvements inchoke coils used in connection with electrical installations requiringthe choking back of high frequency currents which may be induced orimposed upon the high tension transmission lines through eitherharmonies of surgies or creation by imposition of lightning charges uponthe conductors.

A choke coil consists of a coil of wire, the

diameter of which is sufficient to carry the age surges as may beimposed upon the line,

It has been the practice to separate adjoining coils from each other bymeans of impregnated wood or synthetic resinous substances. Frequently,porcelain insulators are utilized to give the choke coil mechanicalrigidity and strength. Impregnated woods and resins are conducive torotting, due to the sulphurous and nitrous gases frequently surroundingpower station equipment. Similarly, choke coils that depend uponporcelain to hold them together fail .because of the mechanical strainimposed on a highly fragile material such as porcelain, which fails whensubjected to shock, a condition to be expected in equipment intended toreact to lightning.

With the foregoing in mind it is thepurpose of the present invention toprovide a frame of material upon which the coils of wire are supportedand which will withstand any possible stress and strain to which adevice of this character is ever subjected. I accomplish this purpose bymeans of the frame hereinafter described and claimed and one embodimentof which is illustratively exemplified in the accompanying drawings inwhich Figure l is a substantially longitudinal sectional view of a chokecoil; and

7, 1929. Serial No. 390,898.

Figure 2 is an end elevational view of the frame and coil.

It should be briefly stated that the present invention does notappertain to any particular design of frame or coil, but relates only toa frame of this character constructed of a substance having very highresistance to electric current along with great mechanical strength, andcomposed in the main of metallic elements.

Referring to the drawings, 10 denotes a choke coil comprising aplurality of coils 11 of' high conducting wire for the conduction of themain line current and a frame. 12 supporting the coils. The frame 12 ismade of a high strength, highly resistant metal, which renders the.frame free from decay and rot. The metal of which the frame is madecomprises preferably a copper alloy, containing elements that increasestrength and resistance simultaneously. The copper may be combined withphosphorus,

silicon, manganese, nickel, and tin to produce a bronze. This bronze hasthe characteristic of having less than 3% of the conductivity of purecopper and at the same time being in the major part constituted ofcopper, it may be brought into contact'with the copper choke coil 11without invitin electrolysis which takes lace between dissimilar metals.

A c oke coil frame made of the bronze just described will be an allmetal device unaffected by exposure to all climatic and atmos-v phericcondltions. It will be clear to one skilled in the art that the currentwould confine itself to the choke coil wire 11 and the leakage acrossthe frame would be harmless as well as negligible. A choke of thischaracter would be free from fire hazards, resulting ordinarily fromhigh voltage flashover,

with great difficulty attack a. high resistance bronze. The slightconductivity of the frame Ion alloy would produce a by-pass that wouldabsorb and dissipate the ener of the stroke thereby acting as a safetyva ve, a condition not possible by using insulating material. 5 r In itspreferred embodiment, the bronze according to my invention consists ofthe following elements:

7 Per cent Copper 90 1 Nickel 8 Silicon 1 Phosphorus Having nowdescribed minvention what I claim and desire to secure y LettersPatent 1. A choke coil of the character described, comprising a frame ofnon-conductive bronze conslsting of copper, phosporus, nickel, andsilicon.

2. A non-conductive bronze for the frames of choke coils consisting of acombination of copper, 90%; nickel, 8%; silicon, 1 and phosphorus, I

, 3. A choke coil of the character described,

comprising a frame of metal'havin electrical conductivity of less than3% 0 that of pure copper, and electrical conductor coils of metal wiresupported on said frame.

In testimony whereof he has aflixed his signature.

' ABRAHAM BERNARD DIBNER.

